M57_en.pdf

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BMW Service

Course contents/Background material

Information status:

09/98

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Introduction

BMW is successively developing a new family of diesel engines with direct injection (DI) that will include 4-cylinder,

6-cylinder and 8-cylinder engines.

Following the successful introduction of the M47D20

4-cylinder engine, a new 6-cylinder engine will soon be phased into series production.

This engine features all the design characteristics of the second generation of direct injection diesel engines and represents the currently most advanced diesel technology available in passen-ger vehicles.

Thanks to its outstanding performance and high comfort proper-ties in conjunction with excellent exhaust quality and integral fuel economy, this engine enjoys a leading position in the competitive environment.

Fig. 1: Competitive situation M47/M57

Initially, the new M57 engine will be installed in the form of a top-of-the-range diesel engine in the 5 and 7 Series. The M67 will enhance the top end of the diesel engine range in the 7 Series. Parallel to this, the well-proven indirect injection engines (IDI) will still remain in the product range.

spec. output Displacement 6-cyl 4-cyl max. output KT-3692

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Objectives

The layout and design particularly of the six-cylinder engine is based on the following primary objectives:

• The creation of a top-of-the-range diesel engine for all BMW model series

• Maintaining the leading competitive position with regard to output power and torque development as well as comfort in the entire diesel vehicle segment

• Securing marketability by the use of future-oriented technical concepts incorporating further development capabilities

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Concepts

The concept features of the new engines correspond to those of second generation DI diesel engines.

The advantages in fuel consumption offered by the first series-produced DI diesel engines were offset by a series of disadvan-tages regarding acoustic comfort, performance, emission, pas-senger compartment heating and costs compared to modern IDI diesel engines.

In contrast to this, with second generation DI diesel engines it has been possible to improve all customer-relevant features, with the exception of costs, by incorporating new or further-developed technical concepts.

Fig. 2: Technical concepts

The superiority of these engines is the result of non-compromis-ing basic engine design (modular system) in conjunction with progressive technical concepts.

4-valve technology In-line design Direct injection

2nd generation

Common rail

VNT DDE

Further development

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Engine views

Fig. 3: M57 engine - General view

Fig. 4: M57 engine - Sectional view

KT-3748

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Fig. 5: M67 engine - General view

Fig. 6: M67 engine - Sectional views

Dummy-Graphik

Graphic currently not available. KT-1463

Dummy-Graphik

Graphic currently not available. KT-1463

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Technical features

Common features

• Light-alloy cylinder head

• 4-valve technology with centrally arranged injection nozzle • Valves and springs identical to M47

• Exhaust turbocharger with variable nozzle turbine (VNT) • Compression ratio 18:1, compression 20 - 25 bar (operating

temperature)

• Common rail injection system • Air mixture 1.15 ≤ λ ≤ 4

• Cooling duct pistons with central crown bowl • Electronically controlled exhaust gas recirculation • Exhaust re-treatment by means of diesel-specific

oxidation catalytic converter and engine-close primary catalytic converter

• Switchable hydraulic engine mounts

• 7-blade fan wheel with viscous clutch drive

• Average inspection intervals 20 000 up to max. 25 000 km limited to 2 years

• The engine begins to cut out at 4000 rpm. The injected volume is reduced continuously. The cutout limit is reached

at approx. 4800 rpm

M57-specific features

• In-line 6-cylinder engine with cast-iron crankcase • High-pressure fuel pump (CP1)

• Plastic cylinder head cover

• Plastic manifold based on two-shell weld technology

• Cast iron 90º V8 cylinder engine with cracked bearing caps • High pressure fuel pump (CP3)

• Aluminium cylinder head cover • Thin-walled cast air intake plenum • Two-piece oil pan

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DDE control unit

Different control units are used depending on the type of engine: • M57 - DDE 4 (different characteristic maps for E38/E39)

• M67 - DDE 4.1

Technical data

The data of the new M57 and M67 engines are as follows:

Production phase-in of each engine:

The engine values below apply to specific vehicles:

M57 M67 Engine type/valves R6/4 V90-8/4 -Displacement (eff.) 2926 3901 ccm Stroke/bore 88.0/84.0 88.0/84.0 mm Compression ratio 18 : 1 18 : 1 -Engine weight 210 277 kg

Power to weight ratio 1.56 1.58 kg/kW

530d 730d 740d Production phase-in 09/98 09/98 03/99 530d 730d 740d M57 135 kW/4000 rpm 135 kW/4000 rpm 390 Nm / 1750 - 3200 rpm 410 Nm / 2000 - 3000 rpm M67 175 kW/4000 rpm 560 Nm/2000 rpm

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Fig. 7: Type test curve M57/E39

Fig. 8: Type test curve M57/E38

Typprüfwerte M57 / E39 0 50 100 150 200 250 300 350 400 450 500 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 Drehzahl (U/min) Drehmoment (Nm) 0 20 40 60 80 100 120 140 Leistung (KW) Md=390 Mn bei 1750 U/min P=135 KW bei 4000 U/min To rq u e Engine speed rpm Output (KW) Md=390 Mn at 1750 rpm P=135 KW at 4000 rpm KT-3744 Typprüfwerte M57 / E38 0 50 100 150 200 250 300 350 400 450 500 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 Drehzahl (U/min) Drehmoment (Nm) 0 20 40 60 80 100 120 140 Leistung (KW) Md=410 Mn bei 2000 U/min P=135 KW bei 4000 U/min To rq u e Engine speed rpm Output (KW) Md=410 Mn at 2000 rpm P=135 KW at 4000 rpm KT-3745 0 100 200 300 400 500 600 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 Drehzahl (U/min) Drehmoment (Nm) 0 20 40 60 80 100 120 140 160 180 Leistung (KW) Md=560 Mn bei 1750 U/min P=175 KW bei 4000 U/min To rq u e Engine speed rpm Output (KW) Md=560 Mn at 1750 rpm P=175 KW at 4000 rpm KT-3746

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Exhaust emission legislation

Pollutant limits have been further reduced in exhaust emission guidelines. These limits for EU-3 will come into force as from 01.01.2000 for new type approvals.

The DI engines fulfil the more stringent requirements specified in the exhaust emission guidelines by means of the following measures:

• Internal engine measures

• Controlled exhaust gas recirculation (EGR) → (refer to Sec. 8) • Catalytic converter → (refer to Sec. 8)

• Common rail (adaptation of injection characteristics)

Pollutant EU-2 EU-3 EU-3 D

Since 1996 As from approx. 2000 Since 01.07.97 CO 1.00 0.64 0.60 g/km (NO_x + HC) 0.70 (0.90)* 0.56 0.56 g/km PM 0.08 (0.10)* 0.05 0.05 g/km PM: Particle mass

*) Different limits applied in part to direct injection diesel engines

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Notes on exhaust emission standards/test cycles

EU-3 D

• Since 01.07.97 in Germany only (for tax reasons) • Testing at room temperature 20 - 30 ºC

• Cold run (40 sec. idling speed without measurement, conditioning)

• 2 test cycles (urban/extra-urban)

• Total duration: 11 km in 20 min.

Average speed: 32 km/h

Max. speed: 120 km/h

EU-3

• As from approx. 2000

• Tendency to more stringent values • 40 sec. idle speed run dropped

The values of the EU-3 D standard and EU-3 standard are not comparable due to different test cycles.

EU-4

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Engine components

System structure

The engine consists of the following main components: • Engine block

• Cylinder head gasket • Cylinder head

• Cylinder head cover • Valve gear

• Crankshaft • Flywheel

• Connecting rods with bearings • Pistons with rings and pins • Chain drive

• Oil pan

• Timing case cover

Fig. 10: Engine components and add-on parts - M57

Differences between the components for the M57 and M67 engines are listed separately.

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Component description

Engine block

The engine block represents the central component of the power plant. It houses the crankshaft, connecting rods and pistons.

The following features apply both to the M57 and M67:

• Crankshaft position/rpm sensor mounted on crankcase for radial sensing at inner incremental wheel (last crankshaft web) • Oil supply gallery for oil spray nozzles with central pressure

control valve

• Material: Grey cast iron

• Support spar concept as on the M47

(i.e. interconnected horizontal and vertical box profiles) • Cast flange for mounting common rail high pressure pump • Reinforcement shell with integrated oil deflector function,

split design in area of cylinder 1 to 2 (oil pump) • Oil spray nozzles (common part M47)

Fig. 11: Engine block - section M57

Forward direction

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• Cast starter flange on both sides, cast timing case • Integrated water flow control to water pump

• Oil supply gallery for oil spray nozzles with central pressure control valve

• Piston spray nozzles each with two spray openings

Fig. 12: Engine block - view M67

1 - Oil return 2 - Coolant ducts

3 - Timing case cover (cast)

4 - Coolant return, integrated collection duct

5 - Space for oil-to-water heat exchanger directly in water pump feed 6 - Starter flange (LHD or RHD) 1 2 3 4 3 5 6 Forward direction KT-3713

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Fig. 13: Engine block - view M67 (from below)

• Cracked bearing caps

• V-engine-compliant threaded connection of main bearing caps with additional support brackets

Technical data:

1.) 225.0 from centre of crankshaft to sealing surface of cylinder head 2.) 285.0 overall height M57 M67 Cylinder spacing 91 98 mm Crankcase height 2251_{, 285}2 _245.0 _mm Bore 84.0 mm Bank offset 18.0 mm

1 - Cracked bearing cap

Forward direction

1

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Cylinder head gasket

The cylinder head gasket seals off the transition points between the engine block and cylinder head.

• Multi-layer steel gasket

• Water flow cross-sections adapted (cylinder-specific) to requirements facilitating uniform coolant flow

• 3 different gasket thicknesses, selected according to determined piston clearance

Fig. 14: Determining thickness of cylinder head gasket

Piston clearance x 1-hole gasket x≤ 0.92 mm 2-hole gasket 0.92 mm < x≤ 1.03 mm 3-hole gasket 1.03 mm < x 36 Measurement position

Engine longitudinal axis

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Cylinder head

The cylinder head represents the upper limit of the combustion chamber. It accommodates the necessary valve timing elements (valves, injectors, camshafts).

The following features apply both to the M57 and M67: • Cast aluminium, cast timing case

• Coolant flow from exhaust to inlet side

• Central, vertical upright arrangement of common rail fuel injector

• 4-valve arrangement (as on M47)

• Exhaust ports combined in cylinder head (as on M47)

• Cylinder head bolts not accessible with camshafts mounted in position

• Glow plugs (heater plugs) arranged on inlet side • Leak-proof arrangement of oil galleries/holes (e.g. for

hydraulic valve lash adjusters)

• Coolant outlet arranged in centre between cylinders 3 and 4 • Inlet port configuration (1 swirl/1 tangential port) adapted to

common rail injection system

1 - Exhaust ports 2 - Fuel injector 3 - Swirl port (inlet) 4 - Tangential port (inlet)

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• Inlet port configuration (1 swirl/1 tangential port), twin-port arrangement

Fig. 16: Inlet port configuration - view M67 with twin port

Technical data:

M57 M67

V-angle Inlet valves 3.75 degrees

Exhaust valves 3.0 degrees

1 - Exhaust ports 2 - Swirl port (inlet) 3 - Tangential port (inlet) 4 - Glow (heater) plug

1

2

3

4

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Cylinder head cover

The cylinder head cover combines the oil separator and intake silencer in the intake module system.

The following feature applies both to the M57 and M67:

• Mounting on cylinder head by means of decoupling elements

• Plastic housing

• Integrated oil separator,

preliminary separation with cyclone,

fine separation with threaded winding downstream

Fig. 17: Intake module - M57

1 - Cylinder head cover 2 - Air cleaner 3 - Oil filler neck

4 - Preliminary separator (cyclone) 5 - Fine separator (threaded winding) 6 - Pressure control valve

7 - Intake system 1 2 7 4 5 6 3 Forward direction KT-3682

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• Aluminium casing

• Integrated oil separator,

preliminary separation by means of cyclone separator, fine separation with threaded winding downstream

Fig. 18: Intake module - M67

1 - Cylinder head cover

2 - Preliminary separator (cyclone) 3 - Fine separator (threaded winding) 4 - Pressure control valve

5 - Oil filler neck 6 - To clean air line

1 4 2 3 Forward direction 5 6 6 KT-3706

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Valve gear

The valve gear consists of the camshafts, rocker arms as well as the valves and springs.

Camshaft

• Chilled cast iron

• New inlet and exhaust camshafts • Negative cam radius ≥ 67 mm

Rocker arm

• Roller-type rocker arm with one hydraulic valve lash per valve (common part with M47)

• Mounted on valve lash adjuster with oil supply

Valves and springs

• Common part with M47

• Inlet and exhaust valves identical

• Bottom valve plate with integrated valve stem seal

Fig. 19: Valve gear - M47/M57/M67

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• Vacuum pump driven by front of exhaust camshaft

• Vacuum pump driven by front of inlet camshafts 1 - 4

Technical data:

M57 M67

Valve diameter 25.9 mm

Valve seat angle 45 Degrees

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Crankshaft

The crankshaft converts the linear stroke motion of the pistons into rotary motion.

• Threaded connection on front end of crankshaft designed as 4-hole mounting (replaces central bolt)

• Thrust bearing designed as constructed bearing

• Material C38 mod.

• Bearing surfaces and radii inductively hardened Main bearings (as on M47)

• Thrust bearing arranged between cylinders 5 and 6

• RPM signal taken from last crankshaft web, incremental wheel screwed on crankshaft web

Fig. 20: Crankshaft drive - view M57

1 - Cylinder 1 2 - Cylinder 6 3 - Incremental wheel 1 2 3 Forward direction KT-3678

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• Material 42 CrMo 4, nitrocarburized

• Shaft cranked at two levels (similar to M62) • Main bearing, common part with M62

• Thrust bearing with integrated bearing, arranged on flywheel end of main bearing

Fig. 21: Crankshaft drive - view M67

1 - Cylinder 1 2 - Cylinder 4 3 - Cylinder 5 4 - Cylinder 8

5 - Connection for torsional vibration damper

Forward direction 4 3 2 1 5 KT-3680

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Flywheel

The flywheel is located between the engine and gearbox. The task of the flywheel is to increase the rotating mass so as to enable more uniform rotary motion.

Various types of flywheel are used depending on the type of gearbox installed.

• Manual gearbox: Dual-mass flywheel

• Automatic gearbox: Sheet-metal flywheel based on sandwich design

• Automatic transmission (5HP30):

Sheet metal flywheel with integrated incremental wheel, TDC allocation adapted to control unit

Technical data:

M57 M67

V-angle Inlet valves 3.75 degrees

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Connecting rods with bearings

The connecting rod connects the piston to the crankshaft. Each connecting rod is mounted such that it can rotate.

The following features applies both to the M57 and M67: • Big-end bearing half on connecting rod end designed as

sputter bearing

• Connecting rod : Common part with M47 • Material C40 mod.

• Cracked version

• Material C70

• For assembly reasons, obliquely split trapezoidal connecting rod, cracked

Fig. 22: Piston with connecting rod

KT-3679

M57 M67

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Technical data:

M57 M67

Distance between hole centres 135 155 mm

Piston pin (gudgeon pin) diameter 30.0 mm

Crankshaft diameter mm

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Pistons with rings and pins

The piston forms the moving bottom wall of the combustion chamber. Its specially designed shape contributes to ensuring optimum combustion. The piston rings seal off the gap to the cylinder wall so as to ensure high compression and as little gas as possible enters the crankcase.

• Cooling duct piston with rotationally symmetrical piston crown bowl specific to DI common rail

• The lobe in the piston crown bowl is higher than on the M47

Fig. 23: Sectional view of combustion chamber

• The pistons of cylinder bank 1 (1 - 4) and cylinder bank 2 (5 - 8) differ as the valve arrangement is not symmetrical (different valve pockets on piston);

the pistons are identified accordingly

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Chain drive

The rotary motion of the crankshaft is transferred to the cam-shaft via the chain drive. In this way it defines the interaction between the stroke motion of the piston and the movements of the valves.

The following features apply both to the M57 and M67: • 2-piece chain drive

• Tensioning rail made from aluminium die casting with plastic slide lining

• Bushed roller chains

• Chain drive 1: From crankshaft to common rail high pressure pump

• Chain drive 2: From common rail high pressure pump to camshafts

• Double-acting chain tensioner

1 - Camshaft 2 - Chain tensioner 3 - Tensioning rail

4 - Common rail high pressure pump 5 - Crankshaft 6 - Guide rail 7 - Oil pump 7 5 4 3 2 1 I E 6

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• Chain drive 1: From crankshaft to inlet camshaft, bank 1 (cyls. 1 - 4)

• Chain drive 2: From crankshaft to inlet camshaft, bank 2 (cyls. 5 - 8)

• Drive of camshafts with respect to each other by means of spur-toothed gearwheels

• Common rail high pressure pump driven by gearwheels for engine speed adaptation of inlet camshaft, bank 2

• Two chain tensioners mounted in cylinder head from outside

Fig. 25: Chain drive - M67:

E1 1 A E2 2 A 1 - Camshaft 2 - Chain tensioner 3 - Tensioning rail

4 - Common rail high pressure pump 5 - Crankshaft 6 - Oil pump 1 2 3 4 5 6 KT-3712

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Oil pan

The oil pan represents the bottom end of the engine and serves as an oil collection reservoir. The position of the oil pan (sump) depends on the design of the front axle.

• Aluminium die cast with integrated thermal oil level sensor • Oil pan gasket designed as metal-backed gasket (same as on

M47, common part E38 and E39)

• Return flow pipe (E38) so that oil from the oil separator can return to the oil sump below the oil level (blow-by gases)

Fig. 26: Oil pan - M57 in E38

Forward direction Oil return pipe from

oil separator

O-ring

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• Two-piece casing

• Upper section made of pressure die cast aluminium with integrated thermal oil level sensor, sheet metal bottom section (common part with M62)

• Oil pan gasket designed as sheet metal backed gasket, gasket of bottom section of oil pan common part with M62

Forward direction

KT-3709

Forward direction

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Timing case cover (M57)

On the M57 the timing case cover covers the chain drive in the area of the crankcase. On the M67 this cover is integrated in the crankcase.

• Aluminium die casting

• Sealed off from crankcase by means of sheet metal beaded gasket (replace gasket after disassembly)

• Unit and belt tensioner connection on cover

Rear end cover (M67)

The rear end cover houses the rotary shaft seal and seals off the rotating crankshaft from the outside.

• Aluminium die casting

• Sealed off from crankcase by means of sheet metal beaded gasket (replace gasket after disassembly)

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Ancillary components and belt drive

Brief description

Various ancillary components are driven by the crankshaft of the engine with the aid of one or two drive belts.

The belt is routed over deflection pulleys in order to ensure sufficient hold (adhesion) about the drive wheels.

Tensioning rollers subject the belt to the necessary preload.

The ancillary components fulfil various tasks only when the engine is running.

Requirements and Objectives

The following requirements and objectives apply to the ancillary components and belt drive.

• Requirements

- Slip-free drive of ancillary components - Maintenance-free

- Optimum power output of ancillary components • Objectives

- Improvement of noise characteristics

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System structure

The belt drive consists of following components: • Torsional vibration damper

• Starter motor • Alternator

• A/C compressor • Belts

• Tensioning pulleys or one idler pulley

Fig. 29: Belt drive M57 E38/E39

1 - Torsional vibration damper 5 - Power steering pump 2 - Tensioning pulley 6 - Alternator

3 - A/C compressor 7 - Idler pulley 4 - Water pump 1 2 3 4 5 7 6 2 KT-3705

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Fig. 30: Belt drive M67 E38

1 - Torsional vibration damper 4 - A/C compressor 2 - Tensioning pulley 5 - Water pump

3 - Power steering pump 6 - Alternator (water-cooled) 1 2 3 4 5 6 2 KT-3693

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Component description

Torsional vibration damper

The M57 and M67 both feature an adaptive (engine-specific) vibration damper with decoupled belt pulley.

Torsional vibration damper M57 E38/E39

• Dual damper adapted specifically to type of engine • 3 variants of vibration dampers

(integrated pulley for ancillary component drive) • Mounting with 4 central bolts

(tightening torque 45 Nm)

Fig. 31: Torsional vibration damper M57

Vehicle Part number

E39 manual gearbox (S5D 390Z) 2 247 886.1 E39 automatic gearbox (GM-5) 2 247 890.9 E38 automatic gearbox (5HP-24) 2 248 520.9

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Torsional vibration damper M67 E38

• Trosional vibration damper with decoupled pulley • Mounting with 4 central bolts

(tightening torque 45 Nm)

Starter motor

Starter M57 E38/E39

• Starter secured to gearbox casing • Weight-optimised version

Starter M67 E38

• Starter mounted on engine block on cylinder bank 2 side • Common part with M51

• Starter cable (separate power supply line for E-box)

Technical data:

M57 M67

Rated output 2.2 kW

Rated voltage 12 V

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Alternator

(also refer to TLF TA3 M51 TÜ)

Alternator M57 E38/E39 (as on M51)

• Basic compact alternator 95 A with start load response • Special version 140 A alternator with load response

Alternator M67 E38

• Liquid-cooled compact alternator (as on M62)

A/C compressor

• Output-controlled A/C compressor • Maintenance-free drive

Belts

Poly-V-belt drive M57 E38/E39

• Maintenance-free • Automatic retensioning

(concept based on M47) • Two belt levels

Rear: Water pump, power steering pump,

Alternator

Front: A/C compressor

Poly-V-belt drive M67

• Maintenance-free • Self-retensioning • Two belt levels

Rear: A/C compressor, power steering pump

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Tensioning pulley or idler pulley

The tensioning pulley is designed as a spring-loaded element, thus rendering the hydraulic connection (M47) unnecessary. The idler pulley arranged on the alternator ensures the belt drive runs more smoothly.

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Engine mounts

Brief description

The engine mount principle used on the M57 and M67 engines is basically the same as from the M51TÜ. The damping charac-teristics of the hydraulic mount are set softer or harder by means of a vacuum. In this way, the vibration transmitted from the engine to the body can be influenced specifically.

Requirements and Objectives

The following requirements and objectives apply to the engine mounts:

• Requirements

- Various damping characteristics of the mounts - Simple design

- Rapid response characteristics

• Objectives

- Comfort at idle speed

- Isolation of engine vibration

- Specific reduction in natural resonance of engine caused by uneven road surfaces and shut-down judder.

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System structure

The system consists of:

• Two hydraulic mounts with controlled damping characteristics • One electric changeover valve

• The control unit (DDE)

• Various electrical and pneumatic lines

Fig. 32: System layout

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Component description

Hydraulic mount

The damping-controlled hydraulic mount consists of: • One conventional hydraulic mount

• One control unit

The hydraulic mount with controlled damping characteristics operates by way of vacuum.

In the basic setting, no vacuum is applied to the hydraulic mount. Bypass (14) is closed. This is achieved by means of spring (10) pressing a rubber diaphragm against the sealing surface of the nozzle plate.

The hydraulic fluid can only flow back and forth via an annular duct (5) between the upper (17) and lower (15) chamber. The mount acts as a conventional hydraulic mount. The damping characteristics are hard.

Fig. 33: Damping-controlled engine mount

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The force exerted by the spring is reduced by applying vacuum to the control unit of the mount (12) so that a bypass now opens permanently. The hydraulic fluid can now flow back and forth via a larger cross section between the two chambers. The damping characteristics of the mount are now softer.

The damping-controlled engine mount is designed to suit specific types of engine:

M57: Pin/pin mount

The left and right mounts differ due to the

asymmetrical arrangement of the engine mounts. (Spring rate: left 180 N/mm / right 220 N/mm)

M67: Pin/flange mount

The left and right mounts are inversely symmetrical due to the symmetrical arrangement of the engine mounts. (Spring rate: 350 N/mm)

The left mount features a stop bowl in order to restrict engine movement when taking up torque.

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Functional description

The vacuum necessary to activate the mounts is taken from a distributor in the vacuum line between the vacuum pump and brake booster.

Vacuum is applied simultaneously to both mounts when idling and in the speed range close to idling. As a result, it is possible to change over between hard or soft damping characteristics.

DDE parameters

Activation of the damping-controlled hydraulic mounts by the DDE is based on the following parameters:

Fig. 34: Sequence diagram/activation, damping-controlled hydraulic mount Switching

value

Remarks

Engine speed 900 rpm Hysteresis (+ 50 rpm)

Vehicle speed 60 km/h Hysteresis (+ 5 km/h)

Power supply (DDE) Vehicle speed v Engine speed n

Engine mount soft (idle speed) Engine mount hard n > 950 v > 65 v < 60 n < 900 KT-210

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Vacuum supply

The necessary volumetric flow is taken from the vacuum line between the vacuum pump and brake booster. For this purpose, the vacuum line of the damping-controlled hydraulic mount is connected to the long outlet of the distributor. The connection for the damping-controlled hydraulic mount is calibrated larger (Ø 0.8) than the connections for the VNT and EGR (Ø 0.5).

Fig. 35: Distributor

The vacuum is within the pressure range from 0.5 to 0.9 bar. It is switched by means of an electric changeover valve.

The vacuum hose between the vacuum line and the electric valve is arranged such that the possibility of rodent damage etc. is excluded with a high degree of probability.

Thottle orifice

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Lubrication system

Brief description

The lubrication system of the M57 corresponds to that of the M47. Geometric adaptations and optimisation measures have been implemented.

Requirements and Objectives

The lubrication system must meet the following requirements and objectives:

• Requirements

- To lubricate sliding surfaces in the engine - To dissipate heat

- To absorb combustion residue of the fuel - To seal off gap between cylinder and piston

• Objectives

- To lower oil consumption

- To increase engine performance - To minimise engine wear

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System structure

The lubrication system consists of following components: • Oil pan with dipstick (see engine components)

• Oil pump

• Oil filter with integrated oil-to-water heat exchanger • Oil spray nozzles

Fig. 36: Lubrication system overview M57 E38/E39

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

1 - Oil pump 9 - Pressure supply to chain tensioner 2 - Oil intake pipe 10 - Riser to cylinder head

3 - Unfiltered oil duct before filter 11 - Pressure supply to vacuum pump 4 - Oil filter with oil cooler 12 - Pressure supply for upper chain lubrication 5 - Precision oil gallery after filter (main oil gallery) 13 - Camshaft bearing

6 - Crankshaft main bearing 14 - Hydraulic valve lash adjuster gallery (HVA) 7 - Pressure supply to exhaust turbocharger 15 - Runout stop, HVA gallery

8 - Piston spray nozzle (hook-type nozzle)

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Fig. 37: Lubrication system overview M67 E38 1 2 11 3 10 6 16 17 5 9 7 4 15 14 12 13 7 8

1 - Oil pump 10 - Piston spray nozzle 2 - Oil intake pipe 11 - Oil pressure control valve 3 - Unfiltered oil duct before filter 12 - Delivery to chain tensioner 4 - Oil filter with oil cooler 13 - Riser gallery into cylinder head 5 - Fine oil gallery after filter (main oil gallery) 14 - Delivery to vacuum pump 6 - Crankshaft main bearing 15 - Camshaft bearing

7 - Delivery to exhaust turbocharger 16 - Hydraulic valve lash adjuster gallery (HVA) 8 - Delivery for chain lubrication 17 - Leak protection HVA gallery

9 - Pressure control valve, piston spray nozzle

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Component description

Oil pump

Oil pump M57 E38/E39

• Oil pump arranged in oil pan • Chain drive

Fig. 38: Oil pump M57

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Oil pump M67 E38

• Duocentric pump

• Arranged at bottom of engine block • Chain drive

• Intake snorkel in oil pan

Fig. 39: Oil pump M67

Technical data

M57 M67

Delivery capacity 85 l/min

Opening pressure of cutout valve 4.2±0.2 bar

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Oil filter with integrated oil-to-water heat exchanger

The oil-to-water heat exchanger is connected to both the oil circuit as well as the water circuit of the engine. This arrange-ment ensures the engine oil is heated faster by the coolant when the engine is cold and is effectively cooled by the coolant when the engine is at operating temperature.

Shortening the warm-up phase greatly contributes to reducing fuel consumption.

Oil filter with oil-to-water heat exchanger M57 E38/E39

• Mounted directly on the engine block

• The water for the oil-to-water heat exchanger is supplied directly from the engine block (crankcase)

• In the same way as on the M47, the water outlet is located on the oil-to-water heat exchanger

Fig. 40: Oil module M57 E38/E39 (with oil-to-water heat exchanger)

1 - Oil filter housing with filter element 2 - Oil pressure sensor

3 - Oil-to-water heat exchanger

1

2

3

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Oil filter with oil-to-water heat exchanger M67 E38

• Mounted directly in V-area of cylinder block

• Oil-to-water heat exchanger located in water bath of V-area

Fig. 41: Oil module M67 E38 (with oil-to-water heat exchanger)

Oil spray nozzles

The oil spray nozzles for cooling the piston crown are mounted in the engine block. They are designed as hook-type nozzles.

Fig. 42: Oil spray nozzles 1

2

3

1 - Oil filter housing with filter element 2 - Oil pressure sensor

3 - Oil-to-water heat exchanger

KT-3676

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Cooling system

Brief description

The coolant circuit is designed to provide long-term protection against frost and corrosion. The design of the M57 is identical to that of the M51 and in the M67 to that of the M62.

The cooling system has been adapted to the new requirements concerning the cooling capacity and the modified environment (common rail, injection system).

Requirements and Objectives

The following requirements and objectives apply to the cooling system:

• Requirements

- Adaptation to injection system (common rail)

- Simple design (same concept as M51 and M62) - All connection points for water-carrying hoses

designed as plug-in connections as on the M47 - Further reduction of emissions and fuel consumption • Objectives

- Provision of optimum cooling capacity under all operating conditions

(59)

System structure

The cooling system consists of following components: • Water pump

• Thermostat • Radiator • Fan/shroud • Auxiliary heater

• Independent park heating option

Fig. 43: M57 - Coolant circuit with auxiliary heater

Fig. 44: M57 - Coolant circuit with independent park heating option

R adiator ÖWWT H eating heat e x c hanger KT-3867 R adiator _ÖWWT Heating heat e x c hanger KT-3868

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Fig. 45: M67 - Coolant circuit with auxiliary heater

Fig. 46: M67 - Coolant circuit with independent park heating option

The various coolant circuits can be subdivided into several part circuits:

• Engine • Heating

• Expansion tank

• Engine oil cooler (M57 only) • Alternator (M67 only)

• EGR cooler (M67 only)

R adiator ÖWWT H eating heat e x c hanger EGR cooler EGR cooler KT-3869 R adiator ÖWWT H eating heat e x c hanger EGR cooler EGR cooler KT-3870

(61)

Component description

Water pump

The water pumps for the M57 and M67 are arranged on the end face of the crankcase.

• Thermostat integrated in water pump housing

• Leakage is directed through drainage tubes into the pulley

Fig. 47: Water pump - M57

Thermostat

The following features apply both to the M57 and M67: • Thermostat integrated in water pump housing

• Opening temperature 88 ºC

• No characteristic map cooling, i.e. no characteristic map thermostat

The thermostat is correspondingly adapted to the M57 and M67. The thermostat on the M67 is a common part with the M62.

(62)

Radiator

The cooling concept of the M47 has been adapted and further developed for this engine.

The gear oil cooler is integrated in the cooling assembly. The capacity of the intercooler has been adapted to the increased volume and is integrated in the centre of the cooling assembly. The coolant change interval is every 4 years. When changing, the different filling capacities should be borne in mind:

• M57 E38/E39 approx. 9.2 litre

• M67 E38 approx. 16.0 litre

Fig. 48: Arrangement of cooling assembly - rear view M57 E39/E38

Power steering cooling loop Gear oil cooler A/C-condenser Intercooler Assembly frame KT-3865

(63)

• The AUC sensor is located below the centre of the fan shroud. • The expansion tank is mounted behind the headlights

Vehicle-specific fan shrouds with different apertures are installed in the E39 and E38. This is necessary due to the fan displacement by approx. 20 mm. The fan will be damaged if interchanged.

For differentiation purposes, an identification code is cast in the top inside of the fan shroud:

• E39M57 Identification code "A"

• E38M57 Identification code "B"

Fig. 49: Arrangement of cooling assembly - rear view M57

• Expansion tank integrated in fan shroud • 5 back-up flaps integrated in fan shroud

• The AUC sensor located above the centre of the fan shroud. • Brush seal installed in cutout of fan shroud to improve uphill

driving cooling properties

In the E38, the water level (level switch) for the expansion tank is indicated as standard in the instrument cluster.

Radiator Fan shroud

Viscous fan

Intercooler

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Exhaust hood/shutter

No radiator shutters are currently installed in the M57 and M67.

Fan

The M57 and M67 feature a 7-blade plastic fan driven by a viscous clutch. Compared to an electric fan, the viscous fan provides better cooling capacity.

In addition to the viscous fan, an electric fan that is activated by the DDE is arranged in front of the radiator assembly.

Auxiliary heater

An auxiliary heater with connection to the heating circuit is installed as standard in the M57 E38/E39 and in the M67 E38 (as on the M47). It is installed instead of the independent park heating in the vehicle.

The separate auxiliary heater is dropped if the independent park heating option is installed. The independent park heating then assumes the function of the auxiliary heater.

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Fuel system

Brief description of function

The M57 is the very first BMW diesel engine to be equipped with a high pressure accumulator fuel injection system (common rail). With this new fuel injection process, a high pressure pump delivers a uniform level of pressure to the shared fuel line - the common rail - which serves all the fuel injection valves. Pressure develops to the optimum level for smooth operation. This means that each injector nozzle is capable of delivering fuel at spray pressures of up to 1350 bar.

The common rail system disconnects fuel injection and pressure generation functions. Fuel injection pressure is generated

independently of engine speed and fuel injection volume and is available in the "Rail" (high pressure fuel accumulator) for

injection to the cylinders.

The fuel injection timing and volume are calculated in the DDE and delivered to each engine cylinder by the injectors, each of which is actuated by energizing the appropriate solenoid valve.

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Requirements and objectives

Demanding requirements and challenging objectives were set for the fuel system. Here are the most important ones:

• Fuel injection pressure

• Adjustment of fuel injection timing

• and formation of fuel injection characteristics.

Maximum fuel injection pressure should be kept as high as possible to reflect the desired emission and performance characteristics. High fuel injection pressures reduce the size of fuel droplets and shorten the fuel injection period.

It must be possible, within broad limits, to make the injection timing dependent on load, engine speed and temperature (> 20º crankshaft angle).

Ideally, the fuel injection process should start slowly and end abruptly without any slowing in delivery speed. Preliminary fuel injection with a small volume of fuel (1 - 2 % of full throttle volume) helps to reduce combustion noise.

❑

High maximum fuel injection pressure

- reduction of droplet size - short injection period

❑

Fuel injection timing adjustable within broad limits

- > 20º crankshaft angle

- load and engine speed-dependent - temperature-dependent

❑

Fuel injection characteristics can be formed

- initially low fuel injection rate

- steep drop at end of fuel injection period - possibility of preliminary fuel injection

(67)

System structure

The fuel system is sub-divided into 2 sub-systems: • Low pressure system

• High pressure system

The low pressure system features the following components: • Fuel tank

• Advance delivery pump • Outlet protection valves • Auxiliary delivery pump

• Fuel filter with inlet pressure sensor • Pressure relief valve (LP system)

and in the fuel return line • Fuel heating (bimetal valve) • Fuel cooler

• Distributor unit with throttle

The high pressure system features the following components: • High pressure pump (HPP)

• High pressure fuel accumulator (Rail) • Pressure control valve

• Rail pressure sensor • Injector

The system pressure is approx. • in the LP system

- inlet end 1.5 bar < p < 5 bar (relative)

- return end p < 0.6 bar (relative)

• in the HP system 200 bar < p < 1350 bar

The following section describes the components in the direction of fuel flow.

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Fig. 50: Schematic diagram of the M57 1 4 3 8 9 7 5 6 14

M57

2 11 10 12 13 15 16 17 19 20 1 2 22 18 DDE 4.0 2 3 1 - Hochdruckpumpe (CP 1) 5 - Injektor 9 - Kraftstoffilter

13 - Tank mit EKP

17 - NW-Geber 21 - EPDW für AGR 2 - Druckregelventil 6 - Differenzdruckventil 10 - Zusatzförderpumpe 14 - Pedalwertgeber 18 - Ladedrucksensor 22 - UD-Speicher und 3 - Hochdruckspeicher (Rail) 7 - Bimetall-Ventil 11 - Kraftstoffkühler 15 - KW-Inkrementengeber 19 - HFM EPDW für VNT 4 - Raildrucksensor 8 - Vorförderdrucksensor 12 - Drossel 16 - Kühlmittel-Temperatursensor 20 - Turbolader (VNT) 23 - UD-Verteiler

MK-12 / M. Schmitz - Mit freundlicher Unterstützung durch Robert Bosch GmbH

Stand: 08/98 1 - H igh pr es sur e pump (CP1) 5 - I nject or 9 -F uel f ilt er 1 3 - T

ank with EFP

1 7 - C amshaf t sensor 21 - EPD W for EGR 2 - P res sur e contr ol v al v e 6 - Dif fer ential pr es sur e v al v e 1 0 -A uxiliar y deliv er y pump 1 4 - A cceler at or pedal sensor 1 8 - Char ge pr es sur e sensor 22 - V acuum accumulat or and 3 - H igh pr es sur e accumulat or (Rail) 7 - Bimet al v al v e 1 1 -F uel cooler 1 5 - Cr ankshaf t incr ement al sensor 1 9 - HFM (hot f ilm) EPD W for VNT 4 - Rail pr es sur e sensor 8 - A dv ance deliv er y pr es sur e sensor 1 2 -T hr ottle 1 6 - C oolant t emper at ur e sensor 20 - T urboc har ger (VNT) 2 3 - V acuum distr ibut or KT-3857

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Fig. 51: Schematic diagram of the M67 1 8 9 7 5 6 14

M67

11 10 12 13 15 16 17 19 20 1 2 22 18 1 - Hochdruckpumpe (CP 3.3) 5 - Injektor 9 - Kraftstoffilter

13 - Tank mit EKP

16 - Kühlmittel-Temperatursensor 20 - Turbolader VN T 2 - Druckregelventil 6 - Verteilerblock 10 - Zusatzförderpumpe 14 - Pedalwertgeber 17 - NW-Geber 21 - 2x EPDW für AGR 3 - Hochdruckspeicher (Rail) 7 - Bimetall-Ventil 11 - Kraftstoffkühler 15 - KW-Inkrementengeber 18 - Ladedrucksensor 22 - Ansteuerun g VNT 4 - Raildrucksensor 8 - Vorförderdrucksensor

12 - Drossel mit Entlüftungsventil

19 - HFM

23 - UD-Verteiler

MK-12 / M. Schmitz - Mit freundlicher Unterstützun

g

durch Robert Bosch GmbH

Stand: 08/98 3 4 3 2 23 DDE 4.1 1 - H igh pr es sur e pump (CP3 .3) 5 - I nject or 9 -F uel f ilt er 1 3 - T

ank with EFP

1 6 - C oolant t emper at ur e sensor 20 - T urboc har ger (VN T) 2 - P res sur e contr ol v al v e 6 - Distr ibut or bloc k 1 0 A uxiliar y deliv er y pump 1 4 - A cceler at or pedal sensor 1 7 - C amshaf t sensor 21 - 2x EPD W for EGR 3 - H igh pr es sur e accumulat or (r ail) 7 - Bimet al v al v e 1 1 F uel cooler 1 5 - Cr ankshaf t incr ement al sensor 1 8 - Char ge pr es sur e sen sor 22 - A ctiv ation of VNT 4 - Rail pr es sur e sensor 8 - A dv ance deliv er y pr es sur e sensor 1 2 -T hr ottle with br eather v al v e 1 9 - HFM (hot f ilm) 23 - V acuum dist ribut or KT-3858

(70)

Component description

Fuel tank

The fuel tank in the E39 (M57) and E38 (M57, M67) has been adopted from the relevant M51TÜ version.

Two outlet protection valves in the tank prevent fuel from escaping in the event of a crash (e.g. vehicle rolling over).

Advance delivery pump

The electrical fuel pump (EFP) is located inside the fuel tank in the right side of the tank.

Fig. 52: EFP (roller cell pump) - E39/E38

The EFP transports fuel from the fuel baffle towards the "engine" and operates the sucking jet pumps in the left and right sides of the tank. Both sucking jet pumps deliver fuel to the fuel baffle in the right side of the tank.

The pump is activated by the control unit via the EFP relay (see DDE). 1 5 2 3 4 UMK0120Y 1 - Intake side 2 - Rotor 3 - Roller 4 - Base plate 5 - Delivery side KT-3732

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Auxiliary delivery pump

The auxiliary delivery pump has the task of providing the high pressure pump (HPP) with an adequate amount of fuel:

• In every operating condition • At the required pressure • Over the entire service life

In the M57 and M67, different auxiliary delivery pumps are employed.

M57

The auxiliary delivery pump in the M57 E39/E38 is an "in-line" electrical fuel pump (EFP) because it is arranged in the inlet line to the high pressure pump.

It is located under the vehicle and is designed as a screw spindle pump (high displacement).

Fig. 53: Auxiliary fuel pump - M57 (E38)

The pump is activated parallel to the electric fuel pump by the control unit via the EFP relay (see DDE).

1 2

3 4

1 - Auxiliary delivery pump ("In-line" pump) 2 - Fuel pump heater or park heating 3 - H-piece (with throttle)

4 - Exhaust system for park heating

(72)

M67

The M67 auxiliary delivery pump in the E38 is a gear pump. It is flange-mounted on the high pressure pump (CP3). The gear pump replaces the "in-line" EFP fitted to the M57 engine.

Fig. 54: Auxiliary delivery pump (gear pump) M67

Effect in the case of fault:

• Warning display via DDE lamp

• Power reduction in engine speed range > 2000 rpm (i.e. driving up an incline is possible at < 2000 rpm, at > 2000 rpm the engine would stall)

2 3 1 UMK 1569 Y 1 - Suction chamber 2 - Drive gear 3 - Compression chamber KT-3733

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Fuel filter

The fuel filter is located over the left wheel arch in the engine compartment.

Fig. 55: Fuel filter - location in E38 M57

The fuel filter cleans fuel before the high pressure pump and prevents premature wear to delicate components. Insufficient filtration can cause damage to pump components, pressure valves and fuel injection nozzles.

It does not feature any electrical fuel heating and does not have a water separator. The filter is identical to the one use in the M51TÜ.

Electrical connection is made to the inlet pressure sensor. To prevent paraffin residue from clogging up the filter at low temperatures, there is a bimetal valve in the return line. This valve prevents heated fuel residue from mixing with cool fuel from the tank.

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Inlet pressure sensor

The inlet pressure sensor is arranged in the fuel filter housing behind the filter element. This is a BMW-specific component.

Fig. 56: Fuel filter with inlet pressure sensor - location in E38M57

It has the task of recording inlet pressure to the high pressure pump (HPP) in the fuel line.

This enables the DDE to reduce the fuel injection quantity at excessively low inlet pressures to the point where engine speed and rail pressure are reduced accordingly. The volume required inlet by the high pressure pump is reduced. This makes it possi-ble for the inlet pressure to the HPP to rise back to the required level.

At an inlet pressure of < 1.5 bar, HPP damage is possible as a consequence of inadequate fill.

The engine can stall suddenly if a differential pressure of ≤ 0.5 bar develops between the inlet and the return lines (pump protection).

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Pressure relief valve (LP system)

The pressure relief valve is located between the fuel filter and the high pressure pump. It is located in the connecting line between the inlet line before the HPP and the return line after the HPP.

Tasks:

The pressure relief valve performs the same task as a pressure limiting valve. It limits the inlet pressure to the high pressure pump from 2.0 to between 2.0 and 3.0 bar. This relieves excess pressure by diverting fuel into the return line.

It protects the high pressure pump and the auxiliary delivery pump from overloads.

Effect in the case of fault:

• Excessive pressure reduces the service life of the auxiliary delivery pump

• The hydrodynamic noises in the HPP and the auxiliary delivery pump rise

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High pressure pump

The high pressure pump (HPP) is located at the front left side of the engine (comparable to the distributor-type fuel injection pump).

Fig. 57: High pressure pump (CP1 - M57)

Different HPPs are used for different models of engine: • HPP with flange-mounted pressure control valve

(M57 - CP1, common rail pump) • HPP with element cutout option

(M67 - CP3, common rail pump)

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Differences between CP1 (M57) and CP3 (M67)

1. Not used at present in the M67. Will instead be used in future CR systems in which pressure control is provided by a system of suction-end volume control.

2. Element filling

3. The CP3 is suitable for operation with restricted suction. However, the M67 version does not utilize this special feature of the gear pump to the fullest extent possible.

In addition to the CP1, the CP3 is also being equipped with the following components:

• Gear pump fitted as a fuel delivery pump

• Solenoid valve for suction end flow rate control

(in the M67 currently only available in conjunction with the "ELAB" function. In future CR systems, pressure control will be handled by a solenoid valve, used to control flow rates at the suction end)

Task

The high pressure pump is the interface between the low press-ure and the high presspress-ure sections. It has the task of ensuring that there is always enough fuel delivered at a sufficient pres-sure in every operating mode over the entire service life of the vehicle. This includes the delivery of spare fuel, required for a rapid start and pressure increase in the rail.

CP1 (M57) CP3 (M67)

Delivery principle 3 piston radial pump with eccentric shaft

Max. delivery pressure 1350 bar 1600 bar1

Min. inlet pressure /differential pressure

1.9 bar / 0.5 bar2 0 bar3

Max. engine speed /rated pressure

3300 rpm / 1350 bar 4000 rpm / 1350 bar

(78)

Structure

Fig. 58: High pressure pump - longitudinal section (CP1)

Fig. 59: High pressure pump - cross section

1 4 13 1 2 9 1 1 5 1 0 1 1 2 3 5 4 8 6 7 UMK1572Y

1 - Drive shaft 10 - Pressure control valve 2 - Eccentric cam 11 - Ball valve

3 - Pump element with pump piston 12 - Fuel return (outlet) 4 - Element chamber 13 - Fuel supply (inlet)

5 - Suction valve 14 - Safety valve with throttle bore 6 - Element cutout valve (not in BMW) 15 - Low pressure duct to pump element 7 - Exhaust valve

8 - Sealing unit

9 - High pressure connection to rail

10 11 12 14 15 ₁₃ KT-3735 1 2 3 4 5 6

1 - Drive shaft 4 - Element chamber 2 - Eccentric cam 5 - Exhaust valve 3 - Pump element with pump piston 6 - Inlet

(79)

Function (also refer to animation on trainer CD)

Fuel is delivered via the filter to the HPP intake (13) and the safety valve (14) situated behind it. It is forced through the throt-tle bore into the low pressure duct (15). This duct is connected to the lubrication and coolant circuit of the high pressure pump. It is therefore not connected to an oil circuit.

The drive shaft (1) is driven via the chain drive at more than half of the engine speed (max. 3300 rpm). It moves the three pump pistons (3) up and down with its eccentric cam (2), depending on the cam shape.

If the pressure in the low-pressure duct exceeds the opening pressure of the suction valve (5) (0.5 -1.5 bar), the advance delivery pump can force fuel into the element chamber where the pump piston moves downwards (suction stroke). If the dead centre point of the pump piston is exceeded, then the intake valve closes. The fuel in the element chamber (4) can no longer escape. It is then compressed in the intake line by the delivery pressure. The accumulating pressure opens the exhaust

valve (7) as soon as the pressure in the rail is achieved. The compressed fuel enters the high pressure system.

The pump piston delivers fuel until the upper dead centre point is reached (delivery stroke). The pressure then falls again, which closes the outlet valve. The remaining fuel is no longer subject to pressure. The pump piston moves downwards.

If the pressure in the element chamber falls below the pressure in the low pressure duct, then the intake valve opens again. The whole process is repeated from the beginning.

The high pressure pump constantly generates the system pres-sure for the high prespres-sure accumulator (rail). The prespres-sure in the rail is determined by the pressure control valve.

The high pressure is generated by means of three pump pistons arranged radially within the high pressure pump. Three delivery strokes per revolution ensure low injection torque and uniform load over the pump drive. At 16 Nm, the average torque is only approx. 1/9 of the drive torque required for a comparable distributor pump.

(80)

The power required for the pump drive increases proportionally • to the set pressure in the rail and

• to the pump speed (delivery volume).

On a 2 litre engine (rated speed, rail pressure 1350 bar), the high pressure pump (at approx. 90 % mechanical efficiency) has a power intake of 3.8 kW (compared to a distributor-type injection pump: 2.5 kW at the rated output point). The higher power requirement is attributed to the leakage and control volumes in the fuel injector and the fuel return via the pressure control valve.

Since the high pressure pump is designed for large delivery quantities, there is an excess of compressed fuel when the vehi-cle is idling or only subject to partial load. Since the compressed fuel is no longer subject to pressure once the excess fuel flows away, the energy generated by compression is lost and/or heats the fuel.

This excess delivered fuel is returned to the fuel tank via the pressure control valve and the fuel cooler.

(81)

Element cutout

This version is not used by BMW!

In order to reduce power loss as the result of the excess delivered volume and thus to improve overall efficiency, the delivery capacity could be adapted to the fuel requirements of the relevant engine by implementing the following measures: • Different number of fuel-delivering pump elements

(3 or 4 elements)

• Different gear ratio of pump to engine • Pump element cutout

The number of pump elements as well as the gear ratio are defined in the overall design.

The amount of fuel that is delivered to the high pressure accu-mulator is reduced by disabling one of the pump elements (3). As a result, the intake valve (5) is held constantly open above a speed of approx. 1500 rpm and below a certain injection volume (1/3 full load) so that the fuel drawn in during the delivery stroke cannot be compressed. The fuel then flows back into the low pressure channel.

As the result of disabling a pump element in conjunction with reduced power requirements, the high pressure pump no longer delivers fuel at a constant rate but rather with a delivery pause which leads to higher pressure pulsation in the rail and greater pressure fluctuations in the fuel injector. This results in fluctua-tions in the injected volume that are unacceptable for BMW.

(82)

Pressure control valve

In the M57, the pressure control valve is located at the high pres-sure pump and, in the M67, in the distributor block (see Fig. high pressure accumulator).

Fig. 60: Pressure control valve

Task

The pressure control valve has the task of setting and main-taining the rail pressure according to the load status of the engine.

• If the rail pressure is too high, the pressure control valve opens, which enables some of the fuel to pass from the rail to the fuel tank via a collector line.

• If the rail pressure is too low, the pressure control valve closes and seals the high pressure side from the low pressure side.

Structure

The DDE control unit controls an armature via a coil. The arma-ture presses a ball into the seal, which seals the high pressure side from the low pressure side. When the system is not

activated, the ball is controlled by a spring. The entire armature is coated with fuel from the flanged-on component for lubrica-tion and heat dissipalubrica-tion.

(83)

Function

The pressure control valve has two control circuits:

• One electrical control circuit for setting a variable pressure value in the rail and

• One mechanical control circuit for equalising high frequency pressure fluctuations.

Since the time factor plays an important role in controlling the pressure, the electric control circuit compensates for slow pres-sure fluctuations and changes and the mechanical control circuit compensates for the quick ones.

Non-activated pressure control valve

The high pressure present in the rail or in the high pressure pump output is exerted on the high pressure intake of the pres-sure control valve. Since the deenergized electric magnet is not in effect, the force of the high pressure is greater than the force of the spring, which opens the pressure control valve. The spring's design creates a pressure of max. 100 bar.

Pressure control valve activated

If the pressure in the high pressure circuit is to be raised, the magnetic force and spring force must be increased. The pres-sure control valve is activated and closed until there is a balance between the high pressure force on the one side and the

magnetic and spring forces on the other. The magnetic force exerted by the electromagnet is in direct proportion to the activation current. Variation in the activation current is achieved by PWM. The PWM frequency is 1 kHz i.e. high enough to prevent disturbance from armature movements and/or fluctua-tion in pressure.

(84)

High pressure fuel accumulator (Rail)

The fuel high pressure accumulator (rail) is located beside the cylinder head cover underneath the engine bonnet.

Fig. 61: Fuel high pressure accumulator (rail) - M57

Fig. 62: Fuel-high pressure accumulator (rail) - M67

1

3 4 5 2

1 - Injectors 4 - High pressure pump (CP1) 2 - High pressure accumulator (rail) 5 - Rubber element

3 - Pressure control valve 6 - Rail pressure sensor

6 KT-3700 2 3 4 5 1

1 - High pressure accumulator (rail), bank 1 4 - Pressure control valve 2 - High pressure accumulator (rail), bank 2 5 - High pressure pump (CP3) 3 - Distributor block 6 - Rail pressure sensor

6

M57_en.pdf

BMW Service

Course contents/Background material

Information status:

09/98

Contents

Introduction

Concepts

Engine views

Dummy-Graphik

Dummy-Graphik

Technical features

DDE control unit

Technical data

Exhaust emission legislation

Notes on exhaust emission standards/test cycles

Engine components

System structure

Component description

Engine block

Cylinder head gasket

Cylinder head

Cylinder head cover

Valve gear

Crankshaft

Flywheel

Connecting rods with bearings

Pistons with rings and pins

Chain drive

Oil pan

Timing case cover (M57)

Rear end cover (M67)

Ancillary components and belt drive

Brief description

Requirements and Objectives

System structure

Component description

Torsional vibration damper

Starter motor

Alternator

A/C compressor

Belts

Tensioning pulley or idler pulley

Engine mounts

Brief description

Requirements and Objectives

System structure

Component description

Hydraulic mount

Functional description

DDE parameters

Vacuum supply

Lubrication system

Brief description

Requirements and Objectives

System structure

Component description

Oil pump

Oil filter with integrated oil-to-water heat exchanger

Oil spray nozzles

Cooling system

Brief description

Requirements and Objectives

System structure

Component description

Water pump

Thermostat

Radiator

Exhaust hood/shutter

Fan

Auxiliary heater

Fuel system

Brief description of function

Requirements and objectives

❑

❑

❑

System structure

M57

M67